EXCLUSIVE: 'Zoo' Team Make an Eerie Discovery in the Season 2 Premiere -- Get Your First Look!

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is back!

CBS’ summer drama returns for its sophomore season on Tuesday, and that means more mysterious animal-related pandemics for the team to contend with.

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ET exclusively premieres a sneak peek from the season premiere, where the gang -- led by zoologist Jackson Oz (James Wolk) and new member Dariela (Alyssa Diaz) -- come across an a troubling new development.

“What the hell kind of rain is this?” Dariela says as the group’s jeep is suddenly hit with what appears to be bloody rain as they make their way through the woods. When Jackson investigates further, he comes to a disturbing conclusion: “That’s not rain.”

Jackson and company are forced to walk the rest of the way on foot and things get creepier and weirder. First, there’s the possibility that what they stumbled onto is acid rain, which doesn’t make any logical sense. Then, there’s ice on one of the feathers from a bird -- strange since it’s not even close to freezing.

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Hmmm... something’s clearly not adding up. “Nothing has since we’ve arrived,” Jackson says ominously. Watch the rest of the scene in the video above.

premieres Tuesday at 9 p.m. ET/PT on CBS.